This invention relates to motor graders and, more particularly, to mounting of the saddle structure to the longitudinal main beam of the motor grader.
Conventionally, an articulated motor grader is comprised of a fore-and-aft extending main beam supported forwardly on wheels. The rear portion of the main beam is hinged to a tractor section supported on traction wheels. A saddle structure is customarily mounted to the main beam for suspendably supporting a ground engaging blade through a linkage responsible for angularly adjusting and laterally positioning the blade. A draw bar is swivelably mounted at one end to the forward section of the main beam and at the other end to the linkage.
During the grading operation, blade loads are transmitted to the main beam through the drawbar and linkage. At the forward end, the drawbar transmits axial, lateral and vertical loads to the main beam. Being restrained at its rear end by the linkage, the drawbar transmits, through the linkage and saddle, vertical, lateral and torsional loads to the main beam. Therefore, the main beam, in the area of the saddle structure, is subjected to high, complex loads.
It has been customary to weld the saddle structure or mounting parts for the saddle structure to the main beam. Stress levels were reduced by adding reenforcement to the main beam in the area of the saddle. The use of these techniques represented a substatial cost and, in some circumstances, unwanted additional vehicle weight.